A mechanical timepiece movement generally includes a barrel system driving at least one wheel at the winding output and one wheel at the unwinding output respectively connected to a winding wheel and to an unwinding wheel of a differential gear. A set of wheels connected to an intermediate wheel of the differential gear controls a power reserve display, but no element of the movement is provided to stop the movement when the power reserve is at zero.
EP Patent 0 568 499 B1 describes a power reserve indicator device for a mechanical watch. The indicator device includes at least one star-wheel with an indicator member, which is driven in rotation during the winding or unwinding of the barrel. The indicator member makes it possible to display the power reserve of the watch. However, nothing is provided to ensure that the movement is stopped when the power reserve approaches zero.
CH Patent 698 752 B1 describes a timepiece which includes a power reserve indicator mechanism. It includes two barrels facing each other and connected by a common arbor, which controls the power reserve display mechanism. However, nothing is provided to ensure that the movement is stopped when the power reserve approaches zero.
CH Patent Application 710 320 A2 describes a timepiece, which includes a mechanical energy source, such as a barrel and a control member connected to a control device inside the watch case. The control device includes a power reserve wheel mounted to pivot on the frame and connected to the barrel by a differential gear so that the angular position of the power reserve wheel is dependent on the degree of wind of the barrel. A control cam is mounted to pivot on the same axis as the power reserve wheel. The control cam has a hole extending in an arc of a circle inside which is housed a pin integral with the power reserve wheel. A spiral spring is mounted between the power reserve wheel and the cam. Connected to the control device, there is also provided a stop device, which includes a stop lever, for stopping the movement when the power reserve is close to zero.